Fuel supplying and injecting pump for internal-combustion engines of the fuel-injection type



July 22,1930. J.' C, GROFF 1,771,038

FUH.,` SUPPLYING AND INJECTING PUMP FOR INTERNAL `COMBUSTION ENGINES OF THE FUEL INJECTION TYPE Grignal Filed April 26, 1927 INVENTOR intainted duly .22, 1930 JOSEPH C. GROFF, OF ALLENTOWN, PENNSYLVANIA FUEL SUPPLYING AND NJECTTNG PUMP FOR INTERNAL-COMBEUSTION ENGINES OF THE FUEL-INJECTION T YPE origmaiappucauonmea April 26, iezrserial No. 186,642. inviami and this application sied April e,

' 192s. serial No. 267,983.

Thev present invention relates to improvements in fuel supplying and injecting pumps foninternal combustion engines of the fuelinjectio'n t pe, and more particularly to pumps of t is class which effect supply 'and the so-called airless injection of fuel to engines of this class which must operate over a wide 4range of running speeds.

The'present application constitutes a division of my, originalv co-pending application, Serial No. 186,642, filed April 26, 1927.

Heretofore, difficulty has been experienced in providin a fuel supplying and injecting pump whic would in itself'becapable of effecting desirable adjustments in the rate atv which the fuel is delivered to the engine thereby without employing pumping mechanisms 'of complicated nature. t

Accordingly, the present invention has for aoits objects, the provision of a fuel-` pumping means of simple construction which will be adapted to adjustably control the rate at which it delivers fuel to the engine irrespective of its runninig speed. y A

Other and more detailed objects and 'advantages -of the present invention will be hereinafter lpointed out in the accompanying specificationand claims and shown in the drawings, which, by way of illustration, showl preferred embodiments of my invention. y

In the drawings:

l Fig. 1 shows allateral cross-sectional View of a twocycle port-scavenged internal combustion engine as illustratlvely arranged to loperate my novel fuel pumping device which is shown in longitudinal cross-sectional view.

Fig. 2 shows a longitudinal crcss'fsectional view of a preferred alternative embodiment of my novel fuel-pumping device.

It should be understood that my fue1- pumping device may be applied as well to engines which operate upon the four-stroke cycle. This may be accomplished with only the usual slight modifications' of known character which are involved with the require-5 ment that the pump operate only half as fast as the engine shaft. However, for the sake of simplifying the description of my invention reference will be made hereinafter to the operation of my pump in conjunctionv with an engine of the two-stroke type.

Referring now to Fig. l, liquid fuel is supplied to the pumping chamber adjacent to the pumping plunger 12 through supply pipe 11 and via valve 16. Preferably, the fuel so supplied in pipe 11 should exist at some -rela- `tively low positive pressure in order to miniregulated in accordance 'with the load demand by changing the period of time during .Which the suction-bypass vvalve 47 is closed downwardly onits seat 16. Y. This may be accomplished in any suitable known .manner not pertinent to the present invention and therefore means for doing so are not shown in the drawings.

Here it should-be stated that the fuel injector 14, which is shown mounted in the wall portion 25 adjacent the combustion vspace 24, is of the automatic so-called airless injection type in that the fuel is injected directly into the combustion space 24 by and lupon fuel` pumping action of plunger 12. That is'to say, the rate at which the fuel is so injected into the combu-stion space via injector -l4 /is solely dependent upon the rate of fuel-'pump-4 ing movement of said plunger 12.

According to' the present invention, the fuel-pumping plunger 12 is given reciprocating movements the rate ofwhich may be ad- 'ustably 'varied as may be desired. Thus, in

ig. l, a pivotally mounted linklike member 28 is adapted to be oscillated about its fulcrum point 29 by any suitable driving means such as linklike member 27 which in turn is operated by the crank or eccentric like member 41. The linklike member 28 is also adapted to engage and bear upon another linklike member 34- at the ivotal joint 38. The other end of said linkli e member34 is connected, also pivthe suspendin "engine which drives it,

otally,` to plunger 12 and member 36 which mayV known character.

The aforementioned fulcrum or ivoting point' 29 is adapted to be adjusted aterally with respectto the line of reeiproeatory travel of plunger 12 and drivin link 34 by means of j arm 30. he suspending arm 30 is itselfa apted, to pivot about its stationary fiilcrum pointA 31and-to' also engage the notched control quadrant 32.

Pivoting adjustments of arm 30 change the vertical positionjof they slotted-out portion of link 28 and causes lengthening or shortening ofthe distance between the, operating joints 29, and 38 to respectively effect quicker or slower rates of reciprocatory movement of the operatively bearing joint 38. That is to say, since without such change the pump speed varies directly with the speedl of the the arm 30 would be in the position shown by line 33 for the slowest running speed, in its full line position for full running speed, and intermediate positions for intermediate running speeds. By so doing the rate at which fuel is delivered by Vbe "of 'any suitable the pump to the fuel injector 14 may be main-v tained substantially unchanged irrespective of the running speed of the engine, if soiiesired.

The connecting linklike member 34 is adapted not merely to drive the fuel plunger 12 at various desirable velocities, but also, to prevent' its imparting lateral forces to said plunger. This is accomplished by the oscillatable supporting link 35 near the bearingA joint 38 and by the aforementioned crosshea 36 at the point of connection with plunger 12. In Fig. 1, to simplify the-diagrammatic illustration of .the fuel pumping linkage in order to more clearly show the interrelation of the different parts thereof, the above mentioned supporting link 35 is shown as being jointedto the connecting link 34 at a point between the driving joint 38 and the crosshead 36. However, in practice I prefer to move said point of connection between links 34 and 35 to the left of bearing joint 38', and also, to

locate the fulcrum joint 52 of supporting link 35 somewheres'above link 34 such as at joint 31 as is shown in Fig. 2. By soadoing, there lwill result a desirable reduction in friction and wear at the various jointsf and particularly at the bearing joint 38.

In Figs. 1 and 2 the similarly acting parts bear the same, vreference characters only in Fig. 2 said parts also bear the letter a as a It should be understood that the fuel plunger 12 requires the exertion of considerable force upon it to effect its purpose,- and this force must naturally be transmitted through the driving linkage by means of the various aforementioned joints therebetween. Thus,

it becomes desirable, i

toguided crosshead j f not essential, to limitA not merely the number of the componenti links, but also, to minimize the extent of movements therebetween and at the different reslpective connecting joints.

t is of importance to note vthat Athe respective dead-center positions of the power pistons crank 39 and of the fuel pump driving cranklike substantially S30-crank degrees. With this constructionthe fuel ,pump plunger 12 is adapted to produce a substantially uniform rate of fuel delivery to the fuel injector 14 since the pumping action necessary to effect injection of the fuel thus takes place only during a comparatively small portion of the ,time during which crank 41 is Ypassing through the vicinity of its mid-stroke position. That is to say, the aforesaid mid-stroke position of crank 41 is thus made to substan- ,tially coincide with the top dead center position of the power crank 39, viz, with the corresponding range of fuel supply and/or injection.

I What I claim is A 1. A. fuel supplying and injecting system for internal combustion engines of the fuelinjection type or the like, comprising in combination with driving means, and with valvng, supply duct and injection nozzle means, a fuel `pumping means comprising a link pivotally suspended from an arm, said driving means Vbeing adapted to oscillate said link about said point of suspension, a fuel p umping plunger, guided link means intermediate said oscillating link and said plunger, said guided link means being operatively connected to said plunger and adapted to engage a bearing portion of said first named link and to be given reciprocating movement thereby, said suspending arm being adapted to adjust the position of said point of suspension with respect to the path of said reciprocation, whereby said guided link and said plunger are adapted to produce delivery to said injection nozzle irrespective of the speed ofthe engine.

2.Afuel supplying and injecting system for internal combustion engines of the fuelinjection type or the like, comprising in combination with driving means, and with valving, supply ductand injection nozzlemeans, a Afuel pumping means comprising a link pivotally suspended from an arm, said driving means being adapted to oscillate said link about said point of suspension, a fuel pumping plunger, guided link means intermediate said oscillating link and said plunger, said guided link means being operatively' connected to said plunger and adapted to engage a slotted-out portion of said iirst named link means 41 are outv of phase by desirable rates of fuel and to begiven reciprocating movement thereby, said suspending arm being adapted -to adjust the position of said point of suspenguided link and Froduc desirably ivery to said inthe peed of the reciprocation', whereby said said plunger are adapted to adjustable rates of-fuel de jection nozzle irrespective of engine.

In testimony whereof I herete aHx my signature. JOSE-PH C. GROFF.

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